What country are you in?
Must be some really old-school culture where people mainly marry for money, prestige, and bragging rights...
You wouldnt happen to be an American would you?
Srsly though, the girls are probably just turned off by your friends and are using the nursing thing as an excuse. From your post, it sounds like your friends come on too strong. Who gets rejected on grounds of "marriage" before they even begin dating?
Not saying the girls arnt at fault either, seeing how they all came crawling back once reality came crashing down on them. Its got more to do with their age than their career. Most
girls around 18-22 (just a rough range I'm throwing out) don't know what they want in a relationship.
The same can probably be said of guys too, but Im just mentioning that so I dont get flamed for being a sexist pig.